The present invention relates to remote actuating apparatus capable of responding to multiple types of security codes including security codes generated from storage at a transmitter and from keypad generation at a transmitter.
Remote actuating apparatus such as automatic garage door openers comprise remote transmitters and a receiver which responds to signals from the transmitters to generating actuating signals thereby opening a door. The receivers of such arrangements provide security in their operation by actuating only when a properly transmitted request is received which matches one of the small number of allowable security codes. The security codes are used to deny access by miscreants and to limit the possibility that someone with a similar transmitter would erroneously open garage doors other than his or her own.
Two basic types of security code transmitters are known in the art. One type disclosed in U.S. Pat. No. 4,750,118 to C. Heitschel, et al., includes an arrangement which stores a security code on a long term or permanent basis and which transmits the stored security code in response to the pressing of a transmit push-button switch. The long term storage of the security code can be provided by a computer-type memory within the transmitter or by a set of switches within the transmitter which are only rarely changed. The stored code type of transmitter is extremely easy to use since it requires only the pressing of a transmit button. The security of such an arrangement is also good, given the large number of possible security codes that are provided for with today's remote actuation equipment. However, the code of the stored code-type transmitters remains with the transmitter and should the transmitter be lost or stolen, others can actuate the receiver with which it is paired by merely pressing a transmit button.
The second basic type of code transmitter does not include long term security code storage, but instead, includes a keypad which the user manipulates to define a particular security code which the user has memorized. In essence, the long term storage of the transmitter is replaced with human memory. Thus, the keypad-type transmitter can only be used to open a door by people knowing the proper code to enter. Should a keypad-type transmitter be lost or stolen, it includes no memory of the security code to be used and thus, an individual who comes into possession of the transmitter without the owner's permission cannot automatically control a receiver. Keypad transmitters, however, are much less convenient to use than stored code transmitters because the code must be remembered and re-entered for each use of the keypad transmitter. Also, when a user's arms are full of packages or when the user is driving a car, keypad code entry can be physically difficult.
A need exists for a door actuation arrangement which provides the security against loss or theft of a keypad transmitter while retaining the ease of use of a stored code transmitter.